These are the events in the question above:
<span>D - has disease
</span>
<span>H - healthy (does not have disease)
</span>
<span>P - tests positive </span>
<span>It is the probability that a person has the disease AND tests positive divided by the probability that the person tests positive.
</span>
Sick, + [.04*.91] = .0364
<span>Sick, - [.04*.09] = .0036 </span>
Healthy, + [.96*.04] = 0.0384
<span>Healthy, - [.96*.96] = .9216
</span>
.0364 / (.0364 + .0.0384) = 0.487
Remark
She starts out with x
She spends 10 dollars paying back her brother (that's - 10)
She spends 30 dollars on fuel (that - 30)
She spends 1/2 what's left on a tent ( that's 1/2 (x - 10 - 30) )
She then spent 29.45 on running shoes. 1/2 (x - 10 - 30) + 29.45 is her expenditures.
After all that she has 17.75 left.
Equation
x - 10 - 30 - 1/2(x - 10 - 30) - 29.45 = 17.75
Solve
Begin by adding 29.95 to both sides.
x - 10 - 30 - 1/2(x - 10 - 30) = 17.75 + 29.45
x -10 - 30 - 1/2(x - 10 - 30) = 47.20 Add the like terms on the left.
x - 40 - 1/2(x - 40) = 47.20 Add 40 to both sides. Don't go inside the brackets.
x - 1/2x + 1/2 (40) = 87.20
1/2 x + 20 = 87.20 Subtract 20 from both sides.
1/2 x = 67.20 Multiply by 2
x = 134.40
x^2-9x-6=0
Use the quadratic formula to get (9+sqrt(105))/2 or (9-sqrt(105))/2
Answer:
xy = 3
d/dt(xy) = d/dt(3)
ydx/dt + xdy/dt = 0
y = 3/x so substitute 3/5 for y, 5 for x, and 5 for dy/dt; and solve for dx/dt.
3/5(dx/dt) + 5(5) = 0
3/5(dx/dt) = -25
dx/dt = -125/3
Step-by-step explanation:
this should be able to help you :)
